Physics for the Life Sciences I
Fall 2010
Adam T. Whitten
PEngl 101
Resources
• Text – College Physics 8th Ed. w/WebAssign by
Serway & Vuille
• Course Manual – contains detailed information
• My website – same info as manual plus
additions (e.g., test solutions)
• WebAssign website
– Self register using class code and access code
– Class codes:
Section 03A (11:20)
csbsju 1747 6239
Section 04A (1:00)
csbsju 5704 3356
• Lab Manual: purchase 2 lab notebooks
What is Physics?
• Study of laws governing interactions of
______________
• Understanding stated in terms of evolving
______________
• Data either supports or disproves a theory
– ____________________
What We’ll Study
Physics
Classical
Modern
Mechanics
Electricity and
Magnetism
Quantum
Mechanics
Relativity
Optics
Thermodynamics
Atomic, Nuclear, &
Elementary Particle
Solid State
Condensed Matter
Cosmology
Physics 105
Physics 106
Units – Système International (SI)
Base and derived units listed in Appendix D, p. A.21
Measure:
Prefixes:
distance ↔ ___________
mega (M) =
mass ↔ ___________
kilo (k) =
time ↔ ___________
centi (c) =
milli (m) =
MKS or SI units
micro (μ) =
Dimensional Analysis
• Using _____ to check for errors in your
solution
• Using units to help with ___________
manipulation
Example:
Significant Figures (Digits)
• Definition: a reliably known ________
• Mathematical results only have as many
significant digits as the operand with the
_________ significant digits
• Leading zeroes _________ count
• Zeroes trailing fractional part after decimal
point _________ count
• _________ zeroes always count
Significant Digits (Examples)
How many sig figs are there for each number?
A = 600 J
___________
B = 660 cm
___________
C = 60.1 mm
___________
D = 0.3 s
___________
E = 0.03 s
___________
F = 0.00300 s
___________
Sig Figs and Addition/Subtraction
Sig figs of result determined by operand with
_______________________________.
1.25 + 6.2832 + 31.043
= _______ → _______
0.75 + 5.3728 − 12.269
= _______ → _______
5200 + 80 + 1.002
= ________ → ______
Watch out for units!
4.5 m − 45 cm + 9 mm = ______________________
= _______ → _______
Sig Figs and Multiplication/Division
Result has same number of sig figs as
operand with the _____________ of sig figs.
(650 J)×(0.00300 s)
= _______________
(60.1 mm)/(0.00300 s)
= ___________________
→ ___________________
(660 cm)/(0.03 s)
= ____________________
→ ____________________
(350 cm)/(0.0013 s)
= ____________________
→ ___________________
______________ helps keep track of sig figs!
Unit Conversions
• Always (95% of the time) convert to ___ units
– Prefixes listed in Table 1.4, p. 3
– Conversion factors (inside front cover)
• Use fractional forms to ________ units
• Watch out for units with ___________
Orders of Magnitude
• Represented as powers of ten
• Examples:
Coordinate Systems
• Origin, O – fixed ____________ point
• Set of specified axes w/ ______________
• Instructions for labeling points relative to __
Cartesian Coordinates
Fig. 1.4, p. 13
Polar Coordinates
Fig. 1.5, p. 14
Trigonometry – Right Triangles
• Relates Cartesian and
Polar Coordinates
• Given any two values
x, y, r, θ, the other 2
can be found
Fig. 1.6, p. 14
r x y
2
2
2
Problem Solving Procedure
(Outlined in Course Manual and p. 16 of text book)
•
•
•
•
•
Read the problem
Draw diagram
Label all physical quantities in diagram
Identify the physical principle(s) or law(s)
Equations relating physical quantities are
written down
• Solve the set of equations algebraically
• Substitute in the known numerical values
• Check your answer